/Engine/Source/Runtime/Landscape/Classes/LandscapeComponent.h
void UpdateCollisionHeightBuffer ( int32 InComponentX1, int32 InComponentY1, int32 InComponentX2, int32 InComponentY2, int32 InCollisionMipLevel, int32 InHeightmapSizeU, int32 InHeightmapSizeV, const [FColor](API\Runtime\Core\Math\FColor) *const InHeightmapTextureMipData, uint16 * CollisionHeightData, uint16 * GrassHeightData, const [FColor](API\Runtime\Core\Math\FColor) *const InXYOffsetTextureMipData, uint16 * CollisionXYOffsetData )